Clamshell bucket



3 11, 1957 F. G. WOODSIDE ETAL 3,330,055

CLAMSHELL BUCKET Filed Oct. 51, 1965 2 Sheets-Sheet l INVENTORS ZC/IH/QD F 025M BY k/PNKG. weeps/p5 Arr aPlygs f g? Ma dam y 11, 1967 F. G. WOODSIDE ETAL 3,330,056

CLAMSHELL BUCKET Filed Oct. 51, 1963 2 sheets-sheet 2 United States Patent 3,330,056 CLAMSHELL BUCKET Frank G. Woodside, Milwaukee, Wis., and Richard F. Uren, Bowling Green, Ohio; said Uren assignor to Frank G. Woodside, doing business as Woodside Industries, Milwaukee, Wis.

Filed Oct. 31, 1963, Ser. No. 320,429 7 Claims. (Cl. 37--184) This invention relates to a clamshell bucket or the like with supporting and operating suspension means therefor.

A major objective is to reduce the over-all height of the bucket and its suspension without reducing the capacity and without impairing its power. All of the operating mechanism is preferably hydraulic.

Considerable reduction in over-all height is effected 'by disposing the jaw actuating cylinder in a position in which it lies between the jaw supporting arms and is inverted with respect to standard practice. This requires an unusual system of levers. It is made practicable by a track which guides the free end of the ram piston rod.

In order to enable the jaws of the compact bucket to handle the power provided for their actuation, a number of different organizations were tried before the discovery of the box section arms and box section bracing or reinforcement as hereinafter disclosed.

Consistently with the preferred use of hydraulic power, a hydraulic motor is provided for the rotation of the bucket upon its suspension axis. An unusually high gear reduction ratio is employed and an integral clutch is included which has been found very valuable in protecting the parts against the damage to which so compact an arrangement might otherwise be peculiarly subject.

The suspension system preferably includes means for absorbing shock, this preferably being incorporated between the motor operated rotating mechanism and the dipper stick by which the bucket assembly is preferably supported from the boom.

In the drawings:

FIG. 1 is a view in side elevation of a bucket assembly embodying the invention as it appears connected with a dipper stick and boom mounted on a hoist assembly which is shown at the rear of a fragmentarily illustrated truck bed.

FIG. 2 is a view taken in section on the line 2-2 of FIG. 1.

FIG. 3 is a view taken in section on line 33 of FIG. 2.

FIG. 4 is an enlarged detail view of the suspension mechanism, the side wall of the gear casing and yoke being broken away to the plane indicated at 44 in FIG. 5.

FIG. 5 is a fragmentary detail view taken from the point of view indicated at 55 in FIG. 4.

FIG. 6 is a fragmentary detail view of the reduction gear, drive and clutch in axial section on the line 66 of FIG. 7.

FIG. 7 is a view of the drive taken in section on the line 77 of FIG. 6.

For the purposes hereof, the mechanism is assumed to be mounted on truck bed 8, although this is not essential. A motor pump unit 10 supplies the hydraulic power communicated through a circuit including supply and return lines 12 and 14 to the interior of a column 16 on which the several controls may be mounted. Projecting from the top of column 16 is a rotatable mast 18. The means within the column 16 for the rotation of the mast form no part of the present invention and accordingly are not disclosed. Pivoted to the mast is a boom 20 raised and lowered by a hydraulic ram 22. Pivoted to the boom is a dipper stick 24 raised and lowered by hydraulic "ice ram 26. At the free end 28 of the dipper stick is the assembly which forms the particular subject matter of this invention.

The link 30 suspends a carrier 32 for the housing 34 which contains the driving assembly for rotation of the clamshell bucket. The brackets 36 on the sides of the housing receive bolts 38 which are reciprocable therein, the compression springs 40 being interposed between the brackets and the carrier 32 to relieve the mechanism of shock when the bucket is dropped onto the work.

Carried at the side of the housing 34 is a motor 42 whose driving shaft 44 spans the housing and carries a worm 46 meshing with worm gear 48 as best shown in FIGS. 6 and 7. Worm gear 48 is keyed to an upright shaft 50 which is mounted in the housing and is provided with a double sprocket 52 connected by a double chain 54 with double sprockets 56 relatively rotatably mounted on the driven shaft 58 which carries the bucket assembly. Splined to the shaft 58 at opposite sides of the double sprockets 56 are clutch plates 60 and 62 which are urged into clamping engagement with the double sprocket 56 by compression springs 64. The spring seat 66 is held to the threaded upper end of shaft 58 by means of nut 68. The clutch disk 60 is supported by nut 70.

This arrangement is such that very high torque can be exerted on the bucket supporting shaft 58 for the rotation of the bucket by means of motor 42. However, if the bucket strikes a rock or other obstruction which precludes rotation, the slip clutch provided between disks 60 and 62 and the gear 56 will permit continued rotation of motor 44 and the reduction drive assembly without injury thereto when the bucket comes to rest.

Mounted on bucket rotating shaft 58 immediately below the gear case 34 is a yoke 72 which includes side arms 74 and 76. The space between them is spanned at the lower end of the arms by a first pintle 78 for ram cylinder 80 and second and third pintles 82 and 84 for the links 86 and 88, respectively. These links are pivoted at their upper ends to the box section arms 90 and 92 which support the bucket jaws 94 and 96, respectively. The arms 90 and 92 are pivotally connected to each other and to piston rod 98 of the ram piston by means of a ram pivot pin 100 having projecting ends guided in Ways 102 and 104 on the arms 74 and 76 of the yoke 72. This unorthodox method of supporting the bucket arms has great strength in an unusually compact form.

It is deemed very important to the transmission of stresses to and from the jaws 94 and 96 that the arms 90 and 92 are made of box section stock with their angles reinforced with gussets 106 as shown in FIG. 1. The respective arms are connected to the backs and 107 of the respective jaws by welding 108, as clearly appears in FIG. 2 and are also connected therewith by bracing channels 110 and 112 connected by Welds 114 to the arms and by welds 116 to the bucket jaws. Considerable experimentation preceded the development of this satisfactory arrangement.

It will be observed from FIG. 1 and FIG. 4 that the piston rod 98 of double acting ram 80 is retracted into the ram to separate the arms 90 and 92 for opening the bucket jaws 94, 96. FIG. 1 shows the jaws closed with the ram piston 95 fully extended. FIG. 4 shows the arms at the increased obtuse angle which they assume when the jaws are partially opened. In the course of this opening movement, the arms fulcrum upon the links 86, 88 and they are'guided and equalized as to position by the piston pin 100 riding in the channels 102 and 104 as above described. To engage the jaws with intervening work the ram piston 95 is extended to restore the parts to the position of FIG. 1.

It will be observed that in the course of this movement the obtuse angle between the arms 90 and 92 is decreased and there is ample space for the operating mechanism above the work engaged in the bucket. Thus a very considerablesaving in over-all height is achieved. This be comes very important'in situations in which the apparatus is opera-ting under a bridge or the like which limits the upward movement of the dipper stick 24. There are many such cases in which the bucket of the instant invention can be raised sufliciently high to clear the side of a dirt receiving truck and in which comparable clearance could not be achieved through the use of conventional structures. There are also advantages in having the entire cross section of the ram piston available to receive hydraulic pressure acting in a direction to close the jaws of the bucket.

More power is required to close the jaws than to open them and more power is available because. the whole area of thejpiston face is exposed to pressure in a closing direction.

The position of the bucket may bechanged at will by the operation. of the hydraulic motor 42 and the reduction gearing, even when the bucket is carrying full load. The slip clutch is very important in'this connection 'be-' cause the ratio reduction is so greatthat in the absence of the clutch serious damage to the gearing could result if an obstruction prevented bucket rotation. r

The resilient'mounting comprising bolts 38 and springs 40 has also proved'to be a valuable feature in practice.

We claim:

1. A clamshell bucket or the like comprising the combination with a yoke provided at its top with suspending verse pintles, a ram cylinder pivotally connected with one of said pintles'and provided with a piston and a connecting nod extensible and retractable with the piston, links connected with the other two pintles and thence laterally and upwardly inclined at opposite sides of the ram, bucket jaws disposed beneath the yoke and having arms in pivotal connection with said piston rod and with each other above the ram cylinder, said links being respectively connected above said other two pintles with intermediate portions of the respective arms.

s. A clamshell bucket 'or the like according to claim 1 p in which the yoke is provided with resiliently yieldable suspension means. 5

6. A clamshell bucket or the like comprising the combination with a yoke provided at its top withsuspending means and provided adjacent its bottom with three transverse pintles, a; ram cylinder pivotally connected with one of said pintlesand provided with a piston and a connecting rod extensible and retractable with the piston, laterally inclined links connected with the other two pintles and at opposite sides of the ram, bucket jaws disposed beneath the yoke and having arms in pivotal connection with said piston rod and with each other above the ram;

cylinder, said links being respectively connected with intermediate portions of the respective arms, the yoke being provided with suspension means including a gear casing, a motor'carried by the gear casing, an upright driven shaft provided with bearings in the gear casing and'connected with the yoke, and means for transmitting motion' I from the motorto the shaft for the rotation of the yoke,

said means including a high ratio reduction gearing 'including a driven member relatively rotatable on the shaft and clutch means connected with the shaft and in clamp- 9 ing engagement with said member to provide a slip drive. 7. A clamshell bucket or the like according to claim in which the high ratio reduction gearing includes a worm in driven connection with the motor, a worm gear having V A means and provided adjacent its bottom with three trans- V 2. A clamshell bucket or the like according to claim 1 r in which pivotal connection of the arms to each other and to the piston rod is provided by a piston pin having its ends guided in ways with which the yoke is provided.

3. A clamshell bucket or the like according to claim 1 in which the said arms are of box section stock and provided intermediate the'respective links and respective jaws with gusset-reinforced angles.

I 4. A clamshell bucket or the like according to claim 1 in which the said arms are of box section stock, the said jaws having backs to which, the' respective arms are welded, there being box section braces having welds connecting them with the arms and extending transversely 1 along'the backs of the jaws and having welds in connectiontherewith.

means rotatably mounting it within the housing, sprocket .means connected with the worm gear, the element rotatable with respecttosaid shaft including a complementary sprocket means, chain means'connecting' the first men-' tioned sprocket means with the complementary sprocket means, and disks connected with the driven shaft and'respectively embracing the complementary sprocket means and constituting the slip clutch aforesaid.

References Cited ABRAHAM o. STONE, Fri/o Examiner.

J. R. OAKS, Assistant Examiner. 

1. A CLAMSHELL BUCKET OR THE LIKE COMPRISING THE COMBINATIN WITH A YOKE PROVIDED AT ITS TOP WITH SUSPENDING MEANS AND PROVIDED ADJACENT ITS BOTTOM WITH THREE TRANSVERSE PINTLES, A RAM CYLINDER PIVOTALLY CONNECTED WITH ONE OF SAID PINTLES AND PROVIDED WITH A PISTON AND A CONNECTING ROD EXTENSIBLE AND RETRACTABLE WITH THE PISTON, LINKS CONNECTED WITH THE OTHER TWO PINTLES AND THENCE LATERALLY AND UPWARDLY INCLINED AT OPPOSITE SIDES OF THE RAM, BUCKET JAWS DISPOSED BENEATH THE YOKE AND HAVING ARMS IN PIVOTAL CONNECTION WITH SAID PISTON ROD AND WITH EACH OTHER ABOVE THE RAM CYLINDER, SAID LINKS BEING RESPECTIVELY CONNECTED ABOVE SAID OTHER TWO PINTLES WITH INTERMEDIATE PORTIONS OF THE RESPECTIVE ARMS. 